Ballard ‘Mark

In PEMFCs, Ralph et al. [86] tested a Ballard Mark V single cell with two different DLs a carbon cloth (Zoltek PWB-3) and a carbon fiber paper (Toray TGP-090) all the other operating conditions stayed the same for bofh cases. It was observed that the carbon cloth demonstrated a distinct advantage over the CFP at high current densities (>600 mA/cm ), while at low current densities both DLs performed similarly. If was claimed fhaf this was because the CC material enhanced mass transport properties and improved the water management within the cell due to its porosity and hydrophobicity. 

Figure 5.40. Comparison of the ohmic resistance-corrected Nyquist plots of a Ballard Mark V 6-cell stack at different temperatures a 50 A, b 100 A, c 150 A...

Honda uses Ballard Mark 902 cells in it FCX demonstration 78 kW fuel cell vehicle, which has power storage in an ultra-capacitor of Honda manufacture (see the 2002 press release 31247/24072 as listed on the Honda web site). 

For the Ballard Mark 900/902 stacks (Gibb, 2001) using Grafcell flow plates, a meeting of minds must have occurred between theAFS/Graftech... 

Figure 6.9 Ballard Mark 9000 Automotive Fuel Cell...

FIGURE 6.9 BALLARD MARK 9000 AUTOMOTIVE FUEL CELL.118... 

Ballard Mark 700 series Ballard Mark 900 series Ballard Mark 700 series... 

NECAR 5.2 Fuel-cell/battery 85 kW/ Ballard Mark... 

FCX-V4 Fuel- cell/Honda ultracapacitors 85 kW/ PEM Ballard Mark 900 series... 

VW EU Capri Fuel-cell/battery 15 kW/ Ballard Mark N/A N/A Methanol... 

Other authors have quoted somewhat higher eificiencies, usually based on the LHV of hydrogen, and lower power outputs. For instance, the Ballard Mark 902 module is said to deliver a maximum efficiency of 48% (LHV) at partial load. This equates to 40.6% (HHV). Thermodynamically, the HHV should be used. When electrical and mechanical losses are included, the tank-to-wheels efficiency reduces to around 33%, in line with our stated range. As noted above, DaimlerChrysler claims 60% efficiency for their F 600 Hygenius car, but this figure needs clarification. 

Cooper reported on development work by the former dbb Company aimed at developing a methanol-fiielled bus [581]. Two NECAR 3 fuel processors switched in parallel were coupled to six Ballard Mark 7 stacks resulting in 100 kW of net continuous power. A turn down ratio of 8 1 could be achieved. A two stage air compressor with heat and pressure energy recovery was used as the air supply. 

Figure 1.31. Typical impedance spectra of a PEM fuel cell. The spectra were obtained at 30 °C using a Ballard Mark V six-cell stack with an active area of 280 cm. ...

Amphett JC, Baumert RM, Peppley RF, Roberge PR, Harris TJ. Performance modeling of the Ballard Mark IV solid potymer electrolyte fuel cell. J Electrochem Soc 1995 142 9-15. 

It can be observed fliat PEMFC performance employing carbon cloth GDLs is different from that when using carbon paper GDLs. Ralph et al. [39] showed that at high current density wifli internal humidification in Ballard Mark V cells the carbon cloth offered a distinct advantage compare to carbon paper. They deemed the surface porosity and hydrophobieity of the carbon cloth substrate to be more favorable for the movement of liquid water, and thus both water management and... 

J. Amphlett, R. Baumert, R. Mann, B. Peppley, P. Roberge, T. Harris, 1995. Performance modeling of the Ballard Mark IV solid polymer electrolyte fuel cell I. Mechanistic model development. Journal of the Electrochemical Society, 142 1-8. 

The impact of operating conditions on lifetime is demonstrated effectively by earlier generation Ballard Power Systems fuel cell stacks used in three different applications. In this case, the same Ballard Mark 9 stack technology exhibits dramatic differences in stack lifetime (see Fig. 6.1). In addition to the variation from a very fast dynamic cycle for the car resulting in only 1000 h lifetime, to a... 

This equation is simple, yet has been found to give an excellent fit with the results of real fuel cells. Example values of the constants are given in Table 3.3 for two different types of fuel cell. Those for one cell from a Ballard Mark V fuel cell stack are taken from Laurencelle et al. (2001). 

Constant Ballard Mark V PEMFC at 70°C High temperature, e g. SOFC... 

Figure 1.18 Three generations of Ballard Mark 1030 (1320 W rated power) technology. The Mark 1030 V3 (on left) is 40% lighter and 26% smaller than the previous generation of residential cogeneration fuel cell. (Image courtesy of Ballard Power Systems, Inc.)...

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